Refrigerant may accumulate in an outdoor unit of existing air-conditioning apparatuses under conditions in which the temperature of outdoor air is low and there is a difference between the temperature of outdoor air and the temperature of the inside of a compressor. To prevent accumulation of refrigerant even under such conditions, some existing air-conditioning apparatuses include a heater that is disposed along the outer periphery of a compressor and that heats refrigerant in the compressor, a compressor-side backflow prevention mechanism that blocks flow of refrigerant toward the compressor, and an accumulator-side flow blocking mechanism that blocks flow of refrigerant toward the accumulator. The air-conditioning apparatuses are provided with a structure that is controlled by a power source so as to be entirely closed when the power source is turned off (see, for example, Patent Literature 1).
Some other air-conditioning apparatuses include a refrigeration cycle that branches off from a portion of a refrigerant pipe between a compressor and an outdoor solenoid valve and that sequentially connects an indoor solenoid valve, an indoor condenser, and a check valve through refrigerant pipes so as to be joined to a cooler. The air-conditioning apparatuses control solenoid valves so as to control the direction of flow of refrigerant discharged from the compressor (see, for example, Patent Literature 2).